Fire protection mechanism for heating and ventilating units



Feb. 21, 1933. w. EWALD 1,898,821

FIRE PROTECTION MECHANISM FOR HEATING AND VENTILATING UNITS Filed Aug. 2, 1950 4 s Sheets-Sheet 1 INVENTOR "A TORNEV Feb. 21 1933. w. EWALD 1,898,821

FIRE PROTECTION MECHANISM FOR HEATING AND VENTILATING UNITS Filed Aug. 2, 1950 3 Sheets-Sheet 3 au-uv).

f atentecl Feb. 21, 1933 TO JOHN J. NESBITT, ING, OF Iii-331N135 CORPORATION OF PEIINSYLVANIA \J MG-PI'IELADELPFIA, PENNSYLVANIA, A

FIRE PROTECTION MECHANISM E933 HEATIITG AND VENTILATING UNITS Application filed August 2,

This invention has reference to the art of heating and ventilating, and particularly relates to a heating and ventilating unit improved in the matter of its fresh air inlet and recirculating dampers and the actuating mechanism therefor, so that the unit will provide, among other things, for protectionagainst fire which may occur in the neighborhood of the inlet chamber of the unit, and which will also bar from entrance to the unit air or fluids carrying excessive temperature or temperatures in excess of a predetermined degree. a 7

Among the objects of my invention may be noted the following: to provide a heating and ventilating unit with a fire door protection; to provide such a unit with a fire-resistant or flame-resistant fresh air inlet damper; to provide such a unit with means whereby fluids carrying excessive temperature cannot be drawn into the unit, and which fluids may be completely automatically barred from entrance to the unit immedi ately upon the manifestation of their presence at the freslrair inlet chamber of the unit; to provide such a unit with means whereby a fire door or fire protection damper may beautomatically closed and the motor simultaneously automatically stopped or rendered inoperative, so that the unit cannot draw flame thereinto,'thus protecting the room of installation and the building containing the unit; to provide a heating and ventilating unit with a mechanism for simultaneously operating an inlet and a recirculating damper and so controlling the operation of said dampers that both of them will be shif ed, in predetermined manner, to opposite extremes of functional range; to provide a unit with dampers and controlling mechanism, such as outlined. in the foregoing,

. whereby, when the dampers are started into operation, they must be shifted continuously from one extreme to the other of their movements against a tendency to return to their original or normal position, or be so returned in the event the shifting and controlling mechanism is deterred from causing the complete shift of the dampers from one extreme position to the other; to provide a heating 7 1930. Serial No. 472,710;

and ventilating unit with fresh air and recirculating damper mechanism such that, under certain conditions of operation, the normal functions of tie unit may be interrupted automatically; toprovide a heating and ventilating unit with a fresh air and recirculating damper and themotor controlling switch with connecting means of such nature as to interact, under certain conditions, so that the unit will be closed to the ad mission of iiuid at tl e inlet chamber and the motor of the unit will be put out of action;

and to provide a heating and ventilating unit with mechanism such that the control thereof is through the medium of a fusible link susceptible to the influence of temperature of predetermined degree.

'l/Vith the above objects in view and others which will be detailed during the course of this description, my invention consists in the parts, features, mechanisms, elements and combinations thereof hereinafter described and claimed.

In order that my invention may-be clearly understood, 1 have provided drawings wherem:

V Figure 1 is a viewshowing, in sectional elevation, on the line 171 of Figure 2, so much of a heating and ventilating unit as is necessary to demonstrate my invention;

- Figure 2 is a view showing, in top-plan and horizontal section on the line 22 of Figure 1, an embodiment of my invention;

Figure 3 is a View in sectional elevation, on the line 3-S of s igure 2, the arrows showing the direction of sight; and

Figure i is a view similar to Figure 3, on the line l-% of Figure 2.

Referring to the drawings, the numeral 1 indicates the rectangular casing of a well known form of heating and ventilating unit, a it being understood that the discharge of air, heated orotherwise, from the unit is in a vertical jet from the top of the unit; and it also bein understood that blowers (two of them) indicated at :2 are operated by a motor indicated at 3', the motor and blowers being arranged above, or it may be below, a filter 4; through which the air passes before being driven intothe room of installation of the s will be open,

manually casing wall unit. The unit in this instance is provided at its bottom with a fresh air chamber 5, at the back of which is constructed an inlet chamber 6 provided with any usual form of grille and dampers or bafiles. At the front of the casing a grille is also provided the opening through which is barred by the recirculatin damper 7, while the chamber 5 at its rear en is closed by the inlet and fire damper 8; The two dampers 7 and 8 are pivoted at their lower edge to the bottom of the casing and are cone nected so as to be simultaneously operated, the one to be closed and the other to be opened or vice versa, according to conditions surroundin the unit. The fire damper 8 is composed 0 any suitable fire-resistant material such as asbestos held between steel plates. This is suggestive and not to be taken as a limitation. Preferably, the damper 8 is set somewhat within the chamber 5 so as to leave a space 9 between it and the inlet chamber 6 for the purposes presently described. The damper 7 may be likewise set, see Figure 4. The pivot of damper 8 is at its bottom 10 and at its top edge contacts with a fire-resistant abutment 11 against which it fits tightly and sm iglly.

e dampers 7 and 8, for normal functional purgpses, are connected by a gyratory lever 12 igures 1 and 4, fulcrumed between its ends at 13 on a crank-arm 14 fixed to a shaft 15 journaled in the opposite ends of the casing near its bottom, the lever 12 being pivotally connected to the recirculating damper in any suitable manner at 16 and likewise at 17 to the fire damper 8. The connection and are rangement of the parts is such that when the fire damper is closed the recirculating damper and vice versa, this action of the two dampers being brought about normally by a crank arm 18 connected to the shaft 15 outside the casin at one end thereof, as shown in Figure 2. his manual control of the damper is for the normal functions of the unit, viz., to permit fresh air to enter the unit with the inlet damper open and the damper 7 closed, or to permit recirculation of the air within the room of installation with the recirculating damper open and the damper 8 closed.

The automatic operation of the two dampers 7 and 8, for firev protection purposes, or for the purpose of preventing the admission into the unit of air or fluid of abnormal or excessive temperature, is brought about in the following manner: Bearing in mind that the connecting and actuating mechanism between the dampers 7 and 8 is duplicated with arrangement of the respective elements near opposite ends of the dampers, as shown in Figure 2, it will be understood that the shaft 15 carries a crank arm 19 at one end near the within the chamber 5, said crank arm having an anti-frictional pinat its outer end operating in a slot 20 of considerable size the cable is passed about a pulley 26 journaled on the bottom of the casing near the front of the chamber 5 The cable 24 is then extended to'the rear wall of thecasing diagonally upwardly and passed about a pulley 2 7, and from thence is led along the rear wall of the casing within the space 9 of the chamber 5 and connected to a fusible link 28, in

turn connected to a turn-buckle 29, in turn connected to one end of another cable 30 extended along the said rear wall of the casing to the opposite end of the chamber 5,, at which point the said cable passes about avpulley 31 supported by the casing wall or a suitable bracket supported on said wall, the end of the cable being then connected as at 32, Fig ure 1, to a lever 33 pivoted at 34 to a bracket 35 supported by the back wall of the casing within the chamber 5. The lever 33. at its upper end is engaged with a contact button or pin-36 controlled by a spring 37 within a switch box 38, mechanism in which latter is adapted to control the current passing through the cable conduit 39. to the motor 3. The lever 33 is normally held in the position shown in Figure 1 in contact with the button 36, which latter compresses the spring 37 while the pin closes the circuit to the motor enabling the latter to function to drive the blowers as usual. The cable portions 24 and 30 with fusible link 28 and turn buckle 29 are located as shown in Figure 2, in the space 90f the casing between the fire door 8 and the inlet chamber 6. In this position it is held taut bvthe spring 22 and connections, which also keep the lever 33 in contact with the but ton 36 and the spring 37 under compression as shown in Figure 1. The fusible link and connected cables located in the s ace 9 are directly exposed to flame, heated lasts and temperature existing in the chamber 6 and passing into the chamber 5 when the fire door 8 is open. If the temperature rises sufficiently, in the space 9 to melt the link 28, both cables 24 and 30 will be released whereupon the doors 7 and 8 will be reversed in their positions, the latter closing against the abutment 11 and shutting out all heat or heated 'fiuid from the chamber 5. Simultaneously,

the spring 37 in the switch-box 38 will force the pin 36 outwardly, thus swinging the lever 33 outwardly due to the fact that the latter is no longer held under tension or taut or in normal condition. This opens the motor circuit, cuts out the motor, bringing the latter to a standstill.

In order that the dampers 7 and 8 may not stop in an intermediate position between fullopen and full-closed, I have provided the controlling mechanism shown in Figures 1 and 2, the same being located near the left-hand end of the unit in the chamber 5. It consists of a crank-arm 4O suitably fixed or spotted on the shaft 15 and operating to normally rest and hold the parts in the position of Figure 1. The outer end of the crank-arm is pivotally connected at 41 to the middle of a triangular floating link 42 having a large opening through which the shaft 15 extends. At one vertex of the triangular link, a pull spring 43 is hooked as at 44 to the link, and at its upper end is hooked to a bracket or ear 46 connected to any pendent or conveneiently adjacent portion of the casing or member mounted therein. The spring normally holds the link 42 in the position shown in Figure 1, which is the position corresponding to that of the mechanism shown in Figures 3 and 4, wherein the fire door. 8 is held tightly closed and the recirculating damper is held wide open. If the crank 40 be shifted by the shaft 15 in a clockwise direction corresponding to the shifting of the arm 14 in a clockwise direction, the spring 43 will be distended, the link 42 will be depressed and shifted laterally with the crank 40, while the gyratory lever 12 will be shifted by the crank-arm 14 to cause the fire door, operating as an inlet damper, to be shifted to open position while the recirculating damper 7 will be shifted to closed position. Soon as the pivotal point 41 between the crank-arm 40 and link 42 passes the dead center of shaft 15, the two doors 7 and 8 will quickly shift under the pull of spring 43 to the positions, respectively, just mentioned. The reverse will take place if the crank-pin 41 is shifted in a counter-clockwise direction to just beyond the dead center of the shaft 15; that is to say, the two dampers 7 and 8 will, respectively, be shifted to the positions shown in Figure 1, thus shutting off the entrance of heat and fluid through the inlet chamber to the chamber 5. If the force impelling the shaft be insuflicient to cause the pivotal point 41 to pass the dead center when operating on either the one side or the other thereof, the spring will operate to return the dampers 7 and 8 to the respective positions from which their movement was started. This is true equally of the hand manipulation and the automatic manipulation of the shaft 15 and the dampers operated thereby. It will be understood, however, that as the manual control will always cause the dampers to be operated as desired, so also will the spring 43,

" link 42 and crank 40' be so positioned and related as to cause the shaft 15 to go through a complete operation of opening or closing the respective doors when the emergency arises requiring the inlet damper to operate F as a fire door and the described mechanism to operate to shut down the motor. The proper functional operation for the automatic control of the inlet damper actingas a fire door will, of course, be brought about by the spring 22, links 21 and the connection of the latter to the crank-arms 19, respectively, said mechanism operating instantly upon the shaft 15 to shift the parts into the position of Figure 1 with the damper 8 closed and the damper 7 open, upon the release of the cables 24 and 30 by the fusing of the link 28. Thus, while for the usual functions of admitting fresh air into the unit, or recirculating the air through the unit in the room or space of installation of the latter, the manual control of all the parts and mechanisms described can be brought about as desired, when the link is fused, the damper 8 being open, the automatic operation of the damper 8 to close the same is infallibly brought about by the power of the springs 22 and 43 overcoming all resistance or tendency to retardation in movement of the parts.

It is believed that the foregoing description is ample without going into further details; but, it is desired to lay stress upon the fact that I have produced a mechanism with interacting parts of such nature as to infallibly cut off the inlet of flame or fluid to the unit in the event of a predetermined rise in temperature in the inlet chamber from any cause whatsoever. In addition, I have combined with the mechanism for automatically closing the fire door at thebase of the unit, a mechanism by which the dampers 7 and 8 may normally operate under manual control for the purpose of permitting recirculation of the air in theroom of installation of the unit or the admission of fresh air into the unit which may be treated in the various usual ways within the unit by the operation, automatic or otherwise, of a temperature control or by-pass damper. I lay stress, therefore, on the combination of interacting recirculating and fresh air inlet dampers, the latter operating as a fire door or as an emergency damper, and also upon the fact that I have provided a heating and ventilating unit with automatic means by which the fire door may be shifted into safety position in case of emergency and the motor automatically cut out of circuit and the unit put out of functional operation.

Having thus described my invention, what I claim and desire to secure by Letters Patent is: i

1. A heating and ventilating unit having a fresh air chamber having openings at its opposite ends, a damper pivotally mounted adjacent each of said openings, means connecting the two dampers whereby they may be shifted simultaneously, means for actuating the shifting, means including a fusible link suspended at one of the entrances to said chamber, whereby when the link is melted the actuating means will be set in operation. to close one ofthe dampers and open the other one. 7

2 A heating and ventilating unit such as defined in claim 1 including a motor and connections between the motor and fusible link for simultaneously cutting out the motor when the dampers are actuated,

WARREN EWALD. 

